Microsoft W840DI manual Limitation Of 32-bit Windows OS, Memory, Users Guide, Page

Memory User's Guide

3.1Limitation Of 32-bit Windows™ OS

Below description applies to 32-bit Windows™ OS only, unless otherwise specified. 32-bit Windows™ OS is confined to the limitation of 4GB (232-1) of addressable memory space.

This would not be an issue when you use Windows™ to view the system memory. That is when you have installed 4GB memory as listed above, Windows™ would report the system memory to be 4GB.

However, if you use other application programs, the reported “available memory size” can be somewhat smaller than the total amount of memory you have installed. When this situation occurs, the reported system memory is overlapped by the video memory and appeared to roughly equal to 4GB minus the total video memory taken up by the video memory of VGA cards. Your system supports single and dual VGA card configurations. So the amount of overlapping really depends on the quantity and the size of video memory you have installed in the system.

There is no such limitation in 64-bit Windows™ OS.

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